/**
 * /* eslint-disable
 *
 * @format
 */

import { Buffer } from 'https://deno.land/std@0.110.0/node/buffer.ts';

// Based on the kafka client 0.10.2 murmur2 implementation
// https://github.com/apache/kafka/blob/0.10.2/clients/src/main/java/org/apache/kafka/common/utils/Utils.java#L364

const SEED = 0x9747b28c;

// 'm' and 'r' are mixing constants generated offline.
// They're not really 'magic', they just happen to work well.
const M = 0x5bd1e995;
const R = 24;

export default (key: any) => {
  const data = Buffer.isBuffer(key) ? key : Buffer.from(String(key));
  const length = data.length;

  // Initialize the hash to a random value
  let h = SEED ^ length;
  let length4 = length / 4;

  for (let i = 0; i < length4; i++) {
    const i4 = i * 4;
    let k =
      (data[i4 + 0] & 0xff) +
      ((data[i4 + 1] & 0xff) << 8) +
      ((data[i4 + 2] & 0xff) << 16) +
      ((data[i4 + 3] & 0xff) << 24);
    k *= M;
    k ^= k >>> R;
    k *= M;
    h *= M;
    h ^= k;
  }

  // Handle the last few bytes of the input array
  switch (length % 4) {
    case 3:
      h ^= (data[(length & ~3) + 2] & 0xff) << 16;
    case 2:
      h ^= (data[(length & ~3) + 1] & 0xff) << 8;
    case 1:
      h ^= data[length & ~3] & 0xff;
      h *= M;
  }

  h ^= h >>> 13;
  h *= M;
  h ^= h >>> 15;

  return h;
};
